I suppose, but at that point you're really blurring the line between 'blockchain' and 'authenticated database logs', and it starts to become a mere buzzword.

At this point "blockchain" pretty much refers to a hash chain, transactions signed by private keys, and some kind of distributed consensus, which could be proof of work, proof of stake, or traditional byzantine consensus if you know who all the node operators are.

Yeah, every invoicing software in my country hash chains the documents for validation purposes (it's a requirement for SAF-T[1]), yet we don't call it a "blockchain".

[1] https://en.wikipedia.org/wiki/SAF-T

Because there are no blocks, no transaction ordering and no distributed consensus?

A block is just a structure with a set of transactions, a date and the hash of the previous block. SAF-T has all that, except the "blocks" have a single transaction. Transaction ordering is provided by the chain of hashes - each record/block links to the previous, just like in the Blockchain.

There is no distributed consensus, but that's the point - there doesn't seem to be here either.

'Blockchain' pretty explicitly specifies the data structure, the method of securing a block is an implementation detail. For example Proof of Stake is basically a variation on a M of N signature scheme.

Without an incentive to "mine" blocks (cryptographically solve).. Anyone can write blocks to the network. How would the network ensure a trusted actor is writing blocks?